Methods and apparatus to provison name-servers

ABSTRACT

Methods and apparatus are disclosed to provision name-servers. An example system disclosed herein includes a name-server evaluator to determine capacities of the plurality of name-servers, a provisioner to compute profile assignment values based on a plurality of subscriber identifiers, and an assignor to assign the subscriber identifiers to one of the plurality of name-servers based on the profile assignment values and the capacities.

CROSS REFERENCE TO RELATED APPLICATION

This patent arises from a continuation of U.S. application Ser. No.11/495,133 filed on Jul. 28, 2006, entitled “Methods and Apparatus toProvision Name-Servers” and which is hereby incorporated herein byreference in its entirety.

FIELD OF THE DISCLOSURE

This disclosure relates generally to network routing, and, moreparticularly, to methods and apparatus to provision name-servers.

BACKGROUND

Network carriers (hereinafter “carrier” or “carriers”) typicallyaccommodate a growing customer base by adding hardware resources that,among other things, store customer data and facilitate customerservices. The carriers, such as telecommunication companies providingvoice, video, audio, and/or other data services, may associate each nodeand/or sub-node of the network (e.g., intranet, Internet, etc.) with aresource record. Each resource record provides information relating to acorresponding node location on the network. Nodes and/or sub-nodesinclude web sites, telephones, fax machines, e-mail addresses, and/orcomputers.

The resource records (RRs) noted above may be managed by a domain namesystem (DNS), which is implemented by domain name-servers distributedthroughout the network. The DNS is a system that stores informationassociated with domain names on networks, such as the Internet, in adistributed database located, for example, in the DNS servers. The DNSenables resolution of an internet protocol (IP) address associated witha domain name and contained in a message such as an Internet Protocol(IP) message transmitted in a network such as Internet. Resource recordsstored by a DNS server may include human-readable hostnames for 32and/or 128-bit IP addresses (e.g., IPv4 and IPv6, respectively), domainname aliases, mail exchange records, mail exchange server lists for aparticular domain, authority records, and/or text records. Because eachserver of a DNS has limited storage resources, additional servers areadded from time to time to accommodate network growth.

Managing network growth, such as by allocating new resource records toservers that have adequate storage capacity, includes tedious serverstatus monitoring and design of instructions to dictate which particularrecords are to be stored on which particular servers. For example, acarrier providing services to 5,000 new customers must decide whichservers have capacity to store the new customer data based on anumbering plan area (NPA) (e.g., an area code), and/or an exchange(e.g., a phone number prefix, hereinafter referred to as a “prefix”and/or “NXX”). If existing servers do not have an adequate capacity toaccommodate the new customers, then new servers are added and all priorrules that dictate where new resource records are stored must bemodified to point to the new server(s).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating an example system toprovision name-servers.

FIG. 2 is an example portion of a database table of the example systemof FIG. 1.

FIG. 3 is an example ENUM server of the example system of FIG. 1.

FIGS. 4A and 4B are example profiles which may be invoked by the exampleENUM servers of FIGS. 1 and 3.

FIG. 5 is a flow diagram representative of example machine readableinstructions which may be executed to implement the example system ofFIG. 1.

FIG. 6 is a schematic illustration of an example computer which mayexecute the program of FIG. 5 to implement the example system of FIG. 1.

DETAILED DESCRIPTION

Methods and apparatus to provision name-servers are disclosed. Anexample system includes a name-server evaluator to determine capacitiesof the plurality of name-servers, a provisioner to compute profileassignment values based on a plurality of subscriber identifiers, and anassignor to assign the subscriber identifiers to one of the plurality ofname-servers based on the profile assignment values and the capacities.An example apparatus includes a random number generator to calculate aprofile assignment value based on a plurality of subscriber identifiersand a pseudo random number from the random number generator, and anassignor to assign at least a subset of the subscriber identifiers torespective ones of the name-servers based on a comparison between theprofile assignment value and a threshold value. An example methodincludes retrieving a load capacity for each of the plurality ofname-servers, assigning each of the plurality of name-servers athreshold value based on the load capacity, receiving an identifierassociated with a subscriber, computing a profile assignment value ofthe identifier based on a sum of a string of ASCII characters associatedwith the identifier, and assigning the identifier to one of theplurality of name-servers based on a comparison between the computed sumand the threshold value based on the load capacity.

An example system 100 to provision name-servers is shown in FIG. 1. Thesystem 100 of the illustrated example updates domain name-servers(hereinafter referred to as name-servers) with resource records (RRs)based on network changes and/or growth. In the example of FIG. 1, anexample originating party 102 includes a plain old telephone system(POTS) telephone 104, a fax machine 106, a voice over internet protocol(VoIP) telephone 108, and/or a computer 110. The computer 110 of theillustrated example is associated with an email address 112 and/or a webaddress 114, such as a web page alias. In the example of FIG. 1, anexample destination party 116 includes similar network devices as theexample originating party 102, such as a POTS telephone 118, a faxmachine 120, a VoIP telephone 122, and/or a computer 124. The computer124 of the destination party 116 is associated with a destination e-mailaddress 126 and/or a destination web-address 128, such as a specificinternet protocol (IP) address associated with a web-page alias.

While a calling party (e.g., the originating party 102 originating acall to the destination party 116) may have an alias destinationidentifier, such as a phone number or web-page address, the aliasdestination identifiers are resolved to specific IP addresses before anycommunicative connection can occur between the originating party 102 andthe destination party 116. An alias destination identifier may include anumbering plan area (NPA), which may be, for example, an area code. Thealias destination identifier may, additionally or alternatively, includea central office (CO) prefix, such as a three digit number referred toas an NXX. Moreover, the alias destination identifier may include asuffix identifier, which is typically 4 digits for North Americantelephone numbering systems. Cumulatively, the NPA/NXX/suffix identifiermay represent the alias destination identifier of an originating party,which is typically sufficient for POTS telephone calls. While such10-digit North American telephone numbers are used for conventional POTStelephone calls, some alias destination identifiers may be associatedwith other devices of a network, such as VoIP telephones, cellular(wireless) telephones, pagers, and/or e-mail addresses, etc.Accordingly, the alias destination identifier entered by an originatingparty must be reconciled to determine an associated IP address toaccommodate communicative connectivity with one or more other device(s)of the network.

While the concepts described herein may apply to any type of aliasdestination identifier, such as a phone number, an e-mail address,and/or a web address (e.g., www.att.com), the following examples willdescribe alias destination identifiers having an NPA, NXX, and/orsuffix. The NPA (e.g., area code) and NXX (e.g., CO prefix) typicallyrepresent a geographic area. For example, the NPA “312” represents anarea code for the city of Chicago, while the NXX of “580” represents oneof many COs within that NPA. An originating party 102 in any localitymay attempt to use an alias destination identifier when placing a callto the destination party 116. In the illustrated example, the NPA(and/or NPA plus NXX plus any suffix) is received by an E164 NumberMapping (ENUM) server 130 to aid customers with enhancing widespreadportability of telephone numbers. The ENUM server 130 of the illustratedexample maps telephone numbers to IP addresses. More specifically, theENUM server 130 employs a DNS-based method for mapping telephone numbersto uniform resource locators (URLs) and/or IP addresses. For instance,in an example DNS method, any number can be transformed into a hostnameby reversing the numbers, separating them with dots (i.e., periods), andadding a suffix, such as “e164.arpa.”

Upon receiving a phone number and/or NPA/NXX combination, the ENUMserver 130 of the illustrated example queries an ENUM database 132,which contains name-server (NS) records. Specific NS records exist forevery established NPA/NXX variation. As used herein, an NPA, NPAcombined with an NXX, and/or NPA/NXX/suffix combination will also bereferred to as an “identifier.” These NS records point to one or moreDNS servers (also referred to as name-servers (NSs)). The particular NSpointed to by a given NS record allows specific resource records (RRs)associated with the NPA/NXX variation to be retrieved (an NPA, NPAcombined with an NXX, and/or NPA/NXX/suffix combination will also bereferred to as an “identifier”). Accordingly, if the ENUM server 130queries the ENUM database 132 regarding a particular identifier andreceives a response of “NS 1,” then RRs for that identifier are found inNS 1 (134). The example system 100 of FIG. 1 includes NS 1 (134), NS 2(136), NS 13 (138), NS 14 (140), and NS 15 (142), but persons ofordinary skill in the art will appreciate that any number of NSs may beemployed in view of any particular needs of the carrier. Each of the NSs134-142 that the carrier employs may reside within a private network144, illustrated to the right hand side of the dotted line 146 inFIG. 1. As a result, the NSs 134-142, RRs stored therein, and/or anyother data are protected from attacks from a public network, such asdenial of service (DoS) attacks from the Internet.

In the illustrated example, each of the NS's includes a lightweightdirectory access protocol (LDAP) server 148 and an LDAP database 150 tostore raw DNS records (also referred to herein as RRs). While the LDAPserver 148 and LDAP database 150 are only shown in NS 1 of FIG. 1, inthe example of FIG. 1 all of the NSs 134-142 include similar components.

The LDAP server 148 of the illustrated example employs a standard thatdefines a manner of organizing directory hierarchies and an interfacefor clients to access the directory servers. A client of the LDAP server148 (e.g., the ENUM server 130) may send operation requests to the LDAPserver 148. The LDAP server 148 of the illustrated example will sendcorresponding responses back to the client based on data containedwithin the LDAP database 150. Requests to the LDAP server 148 mayinclude, but are not limited to, bind requests, transport layer security(TLS) initiation requests, searches, compares, adds, deletes,modifications, and/or unbind requests to close a connection. Forexample, the ENUM server 130 of the illustrated example may route amessage to NS 1 (134) based on information returned from the ENUMdatabase 132 in response to a query regarding an identifier of “312580.”More specifically, the ENUM server 130 of the illustrated example mayappend more detailed information, such as a subscriber number “1234” tothe identifier (e.g., “312580”) and request that IP addresses associatedwith the identifier, if any, be returned. If such information isavailable in the addressed NS, it will be returned to the ENUM server130 to allow the originating party 102 to complete their communicationusing the newly discovered IP address of the destination party.

In the illustrated example, additional NSs may be added to existing NSsin a horizontal manner to accommodate for network/subscriber growth.Therefore, if such information is not available in the additional NS(e.g., NS 1), then the NS 1 (134) may query a child NS, such as NS 14(140) and/or NS 15 (142) to obtain the destination address. In otherwords, when requested information is not found in a parent NS, such asNS 1 (134), then the parent automatically routes the LDAP server requestto one or more subsequent NSs to request resource record information forthe particular identifier. If no such information is available, evenafter a query down all NSs of the family, then the parent NScommunicates the lack of such information to the ENUM server 130, whichin turn, informs the originating party 102 that their call should becompleted via, for example, the POTS system rather than via theDNS-based system (e.g., the Internet). On the other hand, if any NScontains specific information associated with the particular identifier,then that information is returned to the originating party 102 so thattheir communication may be completed to the specific IP address of thedestination party 116.

As discussed in further detail below, the ENUM server 130 of theillustrated example includes a provisioner 152 to associate newidentifiers with NSs of the carrier's private network 144. Theprovisioner 152 of the illustrated example builds the NS records of theENUM database 132.

An example NS record 200 is shown in FIG. 2. In the example of FIG. 2, afirst column 202 lists various NPAs, (e.g., area codes) for which thecarrier may provide services for their subscribers. A second column 204lists various NXXs that are associated with the NPA listed within thecorresponding row of the example NS record 200. A central office inNorth America typically follows particular digit assignment rules forthe NXX representation. For example, “N” is typically any number between2 and 9, but “XX” is typically any number between 0 and 9. A thirdcolumn 206 of the example NS record 200 shown in FIG. 2 lists an NSassociated with the identifier of the corresponding row of the exampleNS record 200. A query to the ENUM database 132 containing the NS record200 will return an NS value corresponding to a matched identifier,thereby allowing further inquiry to that particular NS for specific RRinformation. As a result, the RR information obtained, such as aspecific IP address associated with a destination party's device (e.g.,VoIP telephone), allows the originating party 102 to complete itscommunication to the destination party 116.

Because some NPA/NXX combinations will service a particularly densepopulation, in the illustrated example multiple NSs may exist for someidentical identifiers. For example, row 1 (208) and row 2 (210) eachhave the same NPA/NXX combination, but such combinations are representedby NS 1 and NS 14. As discussed above, if an ENUM server 130 query to anLDAP server, such as the LDAP server 148 of NS 1 (134), does not containa match for the NPA/NXX/suffix combination, the LDAP server 148 mayautomatically forward the query to a subsequent NS in a chain of NSs, ifany associated with the NS 1. However, if the LDAP server does notautomatically provide the service of looking for the combination in anychild NSs, and/or if none of the NS in the chain contain the match, thenthe LDAP server 148 may return a failure notification to the ENUM server130. Because the ENUM server database 132 contains an NS record 200showing an alternative NS for the identifier (e.g., “502896”), the ENUMserver 130 makes a subsequent query to NS 14 (140) to search for thespecific NPA/NXX/suffix combination, rather than immediately returning a“failed” signal to the originating party.

An example ENUM server 130 is shown in FIG. 3. In the illustratedexample, the ENUM server 130 includes a communication interface 302, aprovisioner 304, a resolver 306, and a memory 308 to store variousprovisioning profiles, as discussed in further detail below. The exampleprovisioner 304 includes a random number generator 310, an assignor 312,and an NS evaluator 314 to determine remaining storage capacities of theNSs of the carrier private network 144. As discussed above, the carriermay have numerous NSs to accommodate their customers/subscribers. Anyparticular NS, which may include a databases and server, is not limitedto operation in a geographic location of the area code and/or prefix(e.g., NPA/NXX) for which it serves. For example, an NS thataccommodates the NPA/NXX combination “502896,” which corresponds toLouisville, Ky., may reside anywhere in the country. Similarly, otherNSs may reside in various other parts of the country as part of thecarrier's private network 144.

The communication interface 302 enables communication via a network,such as an intranet or the Internet. Communication from/to the exampleENUM server 130 may occur via web-pages (e.g., Active Server Pages),command-line user interfaces, graphical user interfaces, and/or kiosks.Persons of ordinary skill in the art will appreciate that thecommunication interface 302 may include various protective measures(e.g., a firewall) to shield the NSs from outside attack, such as a DoSattack. Accordingly, in the illustrated example, the private network andany data contained on the NSs therein are not accessible to unauthorizedpersons or publicly accessible via the Internet.

As discussed above, the resolver 306 receives a request, such asidentifiers, from the originating party 102. In response, the resolver306 queries the ENUM database 132 for guidance on where RRs for thereceived identifier may be found. One or more NS identifiers returnedfrom the ENUM database 132 query allow the resolver to access theappropriate NS of the carrier's NS network/private network 144. Theadditional information retrieved from the NS facilitates thecommunication attempt by the originating party 102. For instance, theretrieved information may contain a specific IP address that permitscommunication with the destination party 116.

The example provisioner 304 determines where RRs of new identifiers arestored. For example, a carrier's private network 144 may include manyNSs, with each NS having a particular capacity to store new RRinformation. The NS evaluator 314 queries each of the NSs in the NSnetwork 144 for remaining storage capacity. Such capacity queries may beperformed automatically on a periodic basis (e.g., once per day, onceever other day, once per week, etc.). The capacity information is storedin the memory 308. As new subscribers are added to a particular NPA/NXXcombination, the storage capacity of the assigned NS decreasesaccordingly. Geographic locations having a larger population densityand/or a relatively high rate of population growth may requireadditional child NSs to accommodate the new subscribers, such as theexample NS 14 (140) and NS 15 (142) that accommodate subscriber needsfor the NPA/NXX combination serviced by NS 1 (134).

When a new identifier is to be assigned to an NS, the ENUM server 130receives the combination, such as a new NPA/NXX combination generated toaccommodate a rapidly growing city, and passes it to the assignor 312.The assignor 312 applies one or more formulas and/or weights to thereceived identifier to generate a resulting value. The assignor 312 mayalso employ the random number generator 310 with the aforementionedformulas and/or weights to generate the resulting value. Variousformulas and weights may be represented by one or more profiles thataddress capacity constraints of the existing NSs. One approach tocompute a random or pseudo-random number includes converting theidentifier to a string of ASCII characters. The string of characters maybe summed and divided by a constant. While some carriers will find theaforementioned number generation sufficient to produce unique, random,and/or pseudo random output, larger carriers may be concerned withobtaining the same results by using a static constant, and/or any otherdeterministic computation. For example, an identifier “312580”represents a Chicago area code with a “580” prefix. The ASCII sum forthis identifier is 307. However, an example identifier “313480”represents a Detroit area code with a “480” prefix, also having the sameASCII sum of 307. To minimize the possibility of generating duplicativeoutputs, a random number generator may be employed. Many computersand/or programming languages include functions that generate randomand/or pseudo-random numbers. Typically, such output is a floating pointnumber distributed between 0 and 1. The computers and/or programminglanguages that implement the random number generator may also utilize areal-time clock, a mouse input, and/or a keyboard input as anon-deterministic technique to generate the random number. In anotherexample, the constant may be generated by the random number generatorbefore every computation of a new identifier.

New identifiers may be assigned to existing NSs in a balanced mannersuch that the NS loads are substantially equally distributed. Forexample, some existing NSs may be filled to 90% capacity, which may beexpected for NSs that have been in service for a relatively long periodof time, or for NSs that represent an identifier experiencing a highrate of population growth. Other existing NSs may only be filled to 10%capacity, which may, for example, reflect the fact that the NS was addedto the private network 144 recently. Still further, some carriers mayhave several NSs within their private network 144 that all haveapproximately the same remaining capacity (for example, all NSs areapproximately 60% full). The carrier may prefer that this relativelyeven distribution of NS capacity remain balanced so that, for example,no NSs become disproportionately burdened and/or underutilized.

The assignor 312 may receive an identifier, such as, for example,“312580,” and apply a simple addition operation of the individual digitsto yield 19. Applying the output (e.g., “19”) to the random numbergenerator 310 may function as a seed to produce a random value betweenzero and one. The assignor 312 may compare the output of the randomnumber generated to a profile stored in the memory 308, such as theexample profile 400 of FIG. 4A. The example profile 400 may beconfigured to accommodate NS provisioning for a private network 144 ofNSs that are already relatively balanced, wherein the profile seeks tomaintain such balance. The example profile 400 of FIG. 4A includes an NScolumn 402 having a row for each NS of the carrier's private network144, and a threshold column 404 having an entry for each correspondingNS. Ten NSs are shown in the NS column 402 of FIG. 4A, each having acorresponding threshold of approximately 10%. Any resulting valuecalculated by the assignor 312, based on the identifier, anyformula-based manipulation of the representation, and/or any applicationof the random number generator 310 may be applied to a profile to assignnew identifiers to an NS. For example, if the resulting value from theassignor 312 is 0.27, the assignor 312 will associate the receivedNPA/NXX combination with NS 3. Additionally, the assignor 312 willupdate the ENUM database 132 with this new assignment information sothat the resolver 306 can consult the ENUM database 132 when searchingfor originating party 102 queries. As a result, any subsequentoriginating party 102 query for a suffix associated with “312580” willcause the ENUM server 130 to search NS 3 for RR information.

Profiles may be designed pursuant to any particular needs and/orconstraints of a carrier network. Such profiles may be stored in thememory 308 for later use to accommodate network design and growthobjectives of the carrier. For instance, the example profile 410 of FIG.4B illustrates a network design objective that considers NSs havinglittle or no capacity for further growth. Much like the profile of FIG.4A, the profile of FIG. 4B includes an NS column 412 and a thresholdcolumn 414. Row 1 (416) and row 2 (418) represent NSs that still operateon the carrier's private network 144, but have no further room forgrowth, and thus, cannot add new identifiers. On the other hand, threeof the NSs of the example profile 410 (i.e., NS 3 through NS 5) areconfigured to accommodate 30% of any new NPA/NXX combinations, whereasNS 6 through NS 8 are configured to accommodate the remaining 70% of anynew NPA/NXX combinations. Such segmented profile configurations may beindicative of a carrier that has been growing over time while investingin new NS hardware resources when needed. For example, NS 1 and NS 2 maybe filled to capacity because they were the very first two NSs employedby the carrier, while NS 3 through NS 5 may have been brought on-line ata later date, thereby still having some capacity. Furthermore, NS 6through NS 8 each accommodate approximately 20-30% of the total becausethey came on-line most recently and have a relatively significant amountof remaining storage capacity.

The example profile 410 of FIG. 4B may be referred to as a correctingprofile, which addresses a presently unbalanced plurality of NSs.However, execution of the correcting profile 410 may eventually resultin an overall balance, wherein the remaining NS capacities accepting newNPA/NXX combinations converge to a similar level. For example, NS 3through NS 5 may have started out with 50% remaining capacity, while NS6 through NS 8 may have started out with 80% remaining capacity when thecorrecting profile 410 was invoked. Because the capacity levels of NS 6through NS 8 decrease at a faster rate (due to a wider threshold level,thus greater probability of receiving new identifiers) than NS 3 throughNS 5 due to the disproportionate weighting, a capacity convergencebetween NS 3 through NS 8 may occur. As a result, the carrier mayeventually invoke the profile 400 of FIG. 4A, which may be referred toas a maintaining profile. Such a maintaining profile may be particularlyuseful when the NSs of the carrier private network 144 have a relativelysimilar remaining capacity. However, if the carrier adds new NSs inanticipation of significant growth, the carrier may revert back to analternate profile, such as the correcting profile, to bring the new NSscloser to a capacity level of the older NSs.

While the example threshold values of FIGS. 4A and 4B are constrainedbetween values of zero and one, persons of ordinary skill in the artwill appreciate that any threshold values may be employed for theprofiles. Threshold values may be established in various zones accordingto the type(s) of formulas used to calculate a resulting value from theseed NPA/NXX value.

A flowchart representative of example machine readable instructions forimplementing an example NS provisioning 500 is shown in FIG. 5. In thisexample, the machine readable instructions comprise a program forexecution by: (a) a processor such as the processor 610 shown in FIG. 6,which may be part of a computer, (b) a controller, and/or (c) any othersuitable processing device. The program may be embodied in softwarestored on a tangible medium such as, for example, a flash memory, aCD-ROM, a floppy disk, a hard drive, a digital versatile disk (DVD), ora memory associated with the processor 610, but persons of ordinaryskill in the art will readily appreciate that the entire program and/orparts thereof could alternatively be executed by a device other than theprocessor 610 and/or embodied in firmware or dedicated hardware in awell known manner. For example, any or all of the example system toprovision name servers 100, the ENUM server 130, the provisioner 304,and/or the resolver 306 could be implemented by software, hardware,and/or firmware (e.g., it may be implemented by an application specificintegrated circuit (ASIC), a programmable logic device (PLD), a fieldprogrammable logic device (FPLD), discrete logic, etc.). Also, some orall of the machine readable instructions represented by the flowchart ofFIG. 5 may be implemented manually. Further, although the exampleprogram is described with reference to the flowchart illustrated in FIG.5, persons of ordinary skill in the art will readily appreciate thatmany other methods of implementing the example machine readableinstructions may alternatively be used. For example, the order ofexecution of the blocks may be changed, and/or some of the blocksdescribed may be changed, substituted, eliminated, or combined.

The process 500 of FIG. 5 begins at block 502 where the ENUM server 130waits for an NPA/NXX value. If no value is received, the ENUM server 130takes advantage of processing downtime by determining if a status of theNSs in the private network 144 should be checked (block 504). Asdiscussed above, the provisioner 304 of the ENUM server 130 mayperiodically invoke a status check operation to determine capacities ofthe various NSs of the private network 144 (block 506) and save suchresults to the memory 308 (block 508).

When an NPA/NXX value (identifier) is received by the ENUM server 130(block 502), the resolver 306 determines whether the identifier alreadyexists in the ENUM database 132 (block 510). Identifiers already foundin the ENUM database 132 indicate that there exists an associated NS inthe private network 144 that contains one or more RRs related to thereceived identifier, which may be, for example, an NPA/NXX combinationand/or an NPA/NXX/suffix combination. As such, the resolver 306 resolvesthe identifier and returns the RR information to the requesting party(e.g., the originating party 102) (block 512), as described above.However, if the identifier is not found in the ENUM database 132, thenthe identifier is associated with an NS of the private network 144.Persons of ordinary skill in the art will appreciate that newidentifiers received by the ENUM server 130 may be sent by an authorizedcarrier system administrator having appropriate access privileges to theENUM server 130. As such, the new identifier data may be accompanied byauthentication and/or security techniques, including, but not limitedto, secure sockets layer (SSL), digital certificates, passwordprotection, encryption, and/or public key cryptography.

Upon receipt of the identifier (block 502), determining that the valueis not in the ENUM database 132, and determining that the identifier isaccompanied by appropriate authentication parameters thereby indicatingthat the value requires provisioning to an NS (block 510), the assignor312 calculates a value based on the received identifier (block 514). Asdescribed above, the assignor may use any type of mathematical approachto create a resulting random and/or pseudo-random representation. Theassignor may, without limitation, simply convert the identifier toASCII, sum the identifier, multiply and/or divide by various constants,and/or employ the random number generator 310. The calculated assignoroutput value is applied to a profile (block 516) to determine aparticular NS with which the identifier should be associated. Asdescribed above, a system administrator may design various profiles,such as the example profiles of FIGS. 4A and 4B, to accommodate anyprivate network 144 architecture rules and growth plans. A calculatedassignor output value that falls within profile threshold boundariesindicates the particular NS to which the identifier will be assigned(block 518). After the identifier is assigned (block 518), controlreturns to block 502, wherein the ENUM server 130 waits for receipt ofanother identifier.

FIG. 6 is a block diagram of an example computer 600 capable ofimplementing the apparatus and methods disclosed herein. The computer600 can be, for example, a server, a personal computer, a laptop, a PDA,or any other type of computing device.

The computer 600 of the instant example includes a processor 610 such asa general purpose programmable processor. The processor 610 includes alocal memory 611, and executes coded instructions 613 present in thelocal memory 611 and/or in another memory device. The processor 610 mayexecute, among other things, the example process illustrated in FIG. 5.The processor 610 may be any type of processing unit, such as amicroprocessor from the Intel® Centrino® family of microprocessors, theIntel® Pentium® family of microprocessors, the Intel® Itanium® family ofmicroprocessors, the Intel XScale® family of processors, and/or theMotorola® family of processors. Of course, other processors from otherfamilies are also appropriate.

The processor 610 is in communication with a main memory including avolatile memory 612 and a non-volatile memory 614 via a bus 616. Thevolatile memory 612 may be implemented by Synchronous Dynamic RandomAccess Memory (SDRAM), Dynamic Random Access Memory (DRAM), RAMBUSDynamic Random Access Memory (RDRAM) and/or any other type of randomaccess memory device. The non-volatile memory 614 may be implemented byflash memory and/or any other desired type of memory device. Access tothe main memory 612, 614 is typically controlled by a memory controller(not shown) in a conventional manner.

The computer 600 also includes a conventional interface circuit 618. Theinterface circuit 618 may be implemented by any type of well knowninterface standard, such as an Ethernet interface, a universal serialbus (USB), and/or a third generation input/output (3GIO) interface.

One or more input devices 620 are connected to the interface circuit618. The input device(s) 620 permit a user to enter data and commandsinto the processor 610. The input device(s) can be implemented by, forexample, a keyboard, a mouse, a touchscreen, a track-pad, a trackball,isopoint and/or a voice recognition system.

One or more output devices 622 are also connected to the interfacecircuit 618. The output devices 622 can be implemented, for example, bydisplay devices (e.g., a liquid crystal display, a cathode ray tubedisplay (CRT), a printer and/or speakers). The interface circuit 618,thus, typically includes a graphics driver card.

The interface circuit 618 also includes a communication device such as amodem or network interface card to facilitate exchange of data withexternal computers via a network (e.g., an Ethernet connection, adigital subscriber line (DSL), a telephone line, coaxial cable, acellular telephone system, etc.).

The computer 600 also includes one or more mass storage devices 626 forstoring software and data. Examples of such mass storage devices 626include floppy disk drives, hard drive disks, compact disk drives anddigital versatile disk (DVD) drives. The mass storage device 626 mayimplement the ENUM database 132, and/or any of the databases within theNSs.

Although certain example methods, apparatus, and articles of manufacturehave been described herein, the scope of coverage of this patent is notlimited thereto. On the contrary, this patent covers all methods,apparatus and articles of manufacture fairly falling within the scope ofthe appended claims either literally or under the doctrine ofequivalents.

At least some of the above described example methods and/or apparatusare implemented by one or more software and/or firmware programs runningon a computer processor. However, dedicated hardware implementationsincluding, but not limited to, application specific integrated circuits,programmable logic arrays and other hardware devices can likewise beconstructed to implement some or all of the example methods and/orapparatus described herein, either in whole or in part. Furthermore,alternative software implementations including, but not limited to,distributed processing or component/object distributed processing,parallel processing, or virtual machine processing can also beconstructed to implement the example methods and/or apparatus describedherein.

It should also be noted that the example software and/or firmwareimplementations described herein are optionally stored on a tangiblestorage medium, such as: a magnetic medium (e.g., a magnetic disk ortape); a magneto-optical or optical medium such as an optical disk; or asolid state medium such as a memory card or other package that housesone or more read-only (non-volatile) memories, random access memories,or other re-writable (volatile) memories; or a signal containingcomputer instructions. A digital file attached to e-mail or otherinformation archive or set of archives is considered a distributionmedium equivalent to a tangible storage medium. Accordingly, the examplesoftware and/or firmware described herein can be stored on a tangiblestorage medium or distribution medium such as those described above orsuccessor storage media.

To the extent the above specification describes example components andfunctions with reference to particular standards and protocols, it isunderstood that the scope of this patent is not limited to suchstandards and protocols. For instance, each of the standards forInternet and other packet switched network transmission (e.g.,Transmission Control Protocol (TCP)/Internet Protocol (IP), UserDatagram Protocol (UDP)/IP, HyperText Markup Language (HTML), HyperTextTransfer Protocol (HTTP)) represent examples of the current state of theart. Such standards are periodically superseded by faster or moreefficient equivalents having the same general functionality.Accordingly, replacement standards and protocols having the samefunctions are equivalents which are contemplated by this patent and areintended to be included within the scope of the accompanying claims.

This patent contemplates examples wherein a device is associated withone or more machine readable mediums containing instructions, orreceives and executes instructions from a propagated signal so that, forexample, when connected to a network environment, the device can send orreceive voice, video or data, and communicate over the network using theinstructions. Such a device can be implemented by any electronic devicethat provides voice, video and/or data communication, such as atelephone, a cordless telephone, a mobile phone, a cellular telephone, aPersonal Digital Assistant (PDA), a set-top box, a computer, and/or aserver.

Additionally, although this patent discloses example software orfirmware executed on hardware and/or stored in a memory, it should benoted that such software or firmware is merely illustrative and shouldnot be considered as limiting. For example, it is contemplated that anyor all of these hardware and software components could be embodiedexclusively in hardware, exclusively in software, exclusively infirmware or in some combination of hardware, firmware and/or software.Accordingly, while the above specification described example methods andarticles of manufacture, persons of ordinary skill in the art willreadily appreciate that the examples are not the only way to implementsuch methods and articles of manufacture. Therefore, although certainexample methods, apparatus and articles of manufacture have beendescribed herein, the scope of coverage of this patent is not limitedthereto. On the contrary, this patent covers all methods, apparatus andarticles of manufacture fairly falling within the scope of the appendedclaims either literally or under the doctrine of equivalents.

1. A system to provision a plurality of name-servers communicativelyconnected to a name-server network, the system comprising: a name-serverevaluator to determine capacities of the plurality of name-servers; aprovisioner to compute profile assignment values based on a plurality ofsubscriber identifiers; and an assignor to assign the subscriberidentifiers to one of the plurality of name-servers based on the profileassignment values and the capacities.
 2. A system as defined in claim 1,wherein the assignor is to assign the subscriber identifiers to theplurality of name-servers in a substantially equally distributed manner.3. A system as defined in claim 1, wherein the assignor is to assign agreater number of the subscriber identifiers to a first plurality of theplurality of name-servers than to a second plurality of name-servers. 4.A system as defined in claim 1, further comprising a random numbergenerator invoked by the provisioner to compute the profile assignmentvalues for the plurality of subscriber identifiers.
 5. A system asdefined in claim 1, wherein the assignor is to assign the subscriberidentifiers to the plurality of name-servers based on respectivecomparisons between a threshold and the profile assignment values.
 6. Asystem as defined in claim 1, wherein each of the subscriber identifierscomprises at least one of a numbering plan area number, a prefix number,or a suffix number.
 7. An apparatus to provision name-servers,comprising: a random number generator to calculate a profile assignmentvalue based on a plurality of subscriber identifiers and a pseudo randomnumber from the random number generator; and an assignor to assign atleast a subset of the subscriber identifiers to respective ones of thename-servers based on a comparison between the profile assignment valueand a threshold value.
 8. An apparatus as defined in claim 7, furthercomprising a name-server evaluator to query each of the name-servers foran indication of remaining storage capacity.
 9. An apparatus as definedin claim 8, further comprising a name-server profile to assign thethreshold value in an equally distributed manner for each one of thename-servers when the name-server evaluator identifies each one of thename-servers indicate a substantially equal amount of remaining storagecapacity.
 10. An apparatus as defined in claim 8, wherein thename-server profile is to assign a larger threshold value to a first oneof the name-servers than a second one of the name-servers when the firstone of the name-servers has a remaining storage capacity that is lowerthan the remaining storage capacity of the second one of thename-servers.
 11. An apparatus as defined in claim 7, wherein thethreshold value assigned by the name-server profile is a range of valuesbetween zero and one.
 12. An apparatus as defined in claim 7, whereinthe plurality of subscriber identifiers comprise a numbering plan area(NPA) number, and wherein each NPA number corresponds to a subscriber.13. An apparatus as defined in claim 7, further comprising a front-endserver to route a request for an ENUM record associated with one of theplurality of subscriber identifiers.
 14. An apparatus as defined inclaim 13, wherein the front-end server receives a name-server identifierfrom the plurality of name-servers that stores subscriber informationassociated with the one of the plurality of subscriber identifiers. 15.A computer implemented method to provision a plurality of name-servers,comprising: retrieving a load capacity for each of the plurality ofname-servers; assigning each of the plurality of name-servers athreshold value based on the load capacity; receiving an identifierassociated with a subscriber; computing a profile assignment value ofthe identifier based on a sum of a string of ASCII characters associatedwith the identifier; and assigning the identifier to one of theplurality of name-servers based on a comparison between the computed sumand the threshold value based on the load capacity.
 16. A method asdefined in claim 15, further comprising dividing the computed sum by aconstant.
 17. A method as defined in claim 16, wherein the constant isgenerated by a random number generator.
 18. A method as defined in claim15, wherein assigning each of the plurality of name-servers thethreshold value based on the load capacity further comprises assigning agreater threshold window value to a first name-server having a greaterload capacity than a second name-server, the second name-server assigneda lesser threshold window value than the first name-server.
 19. A methodas defined in claim 15, wherein receiving the identifier comprisesreceiving at least one of a numbering plan area (NPA) number, a prefixnumber, or a combination of the NPA number and the prefix number.
 20. Amethod as defined in claim 15, wherein assigning each of the pluralityof name-servers the threshold value based on the load capacity furthercomprises assigning an equal threshold window value to each of theplurality of name-servers when the retrieved load capacity issubstantially equal.